Bentonite is clay containing not less than 70% of montmorillonite. Montmorillonite is superfine flaky aluminosilicate. High waterproofing is conditioned on this. In case of water tempering, water penetrates in interlayer area of montmorillonite, hydrates it's surface and cation-exchange, so that provides swelling of the mineral. During further water dilution bentonite forms firm viscous suspension with thixotropic properties. Montmorillonite has high cation-exchange and adsorption properties.
Owing to above stated properties bentonite has found wide application as viscous gelling agent and filtration diminishing agent in drilling fluids production for well-boring, as binding agent in foundry sands and iron ore pellets and also as hydraulic and adsorption material. In agriculture bentonite is used in mixed fodder production, as bedding for animals, for soil reclamation and also for wine and juice clarification. Besides, bentonite is used in production of high-quality clumping cat litter. It is well known that bentonite has more than 200 spheres of application.
Bentonite where montmorillonite contains -Na exchange cations possess best technical properties. Deposits of natural- sodium betonite on the territory of CIS and Central Asia are located in Trans-Caucasian region. Almost all Russian bentonite is calcium - magnesium. Consumer properties of such bentonite, containing not less than 70% of montmorillonite after soda ash activation might approach to natural-sodium bentonite. Sometimes the clay deposits with 30-60% montmorillonite content are considered bentonite by mistake.